The present invention relates to a terminal locking structure in which a terminal lance is prevented from being deformed when a terminal of an electric connector is removed from a connector housing.
Heretofore, various structures disclosed, for example, in Japanese Patent Unexamined Publication No. Hei. 3-147282, are known as terminal locking structures of electric connectors. As shown in FIG. 5, in a terminal locking structure 31 of a conventional electric connector 40, a first free end 35a of a flexible terminal lance 35 made of a metal plate is engaged with an engagement portion 33 in a connector housing 32 to thereby lock a terminal 34 at a predetermined position in the connector housing 32. The terminal lance 35 of the terminal 34 is made of a metal plate integrated with a box ceiling plate 36 so as to be bent at a desired angle obliquely backward and outward.
A flexible contact plate 39 which cooperates with the box ceiling plate 36 to press and hold a mating contact 50 for the electric connector 40 to thereby electrically connect the maiting contact 50 to the electric connector 40, is bent integrally with a bottom plate 38. An end plate at the first free end 35a of the terminal lance 35 is punched in its center, bent downward and further bent so as to be parallel with the bottom plate 38, so that a second free end 35c is formed. The second free end 35c abuts on a stopper plate 37 supported by a stabilizer 41 of the terminal 34, so that the terminal lance 35 is prevented from projecting out due to its flexibility over a necessary extent. An electric wire caulking portion 42 is provided in the rear portion of the terminal 34 in order to fix an electric wire W and to make electrical connect with a core of the electric wire W.
An unlock hole 45 for removing the terminal 34 is provided under a ceiling 44 of the connector housing 32 at the upper position of the box ceiling plate 36 of the terminal lance 35. Further, an insertion hole 47 for leading the mating contact 50 therein is provided in the front wall 46 of the connector housing 32 whereas a slot 49 for preventing the mis-insertion of the terminal 34 is provided in the center portion of the bottom wall 48.
In the thus configured terminal locking structure 31, when the terminal 34 with the electric wire W caulked by the electric wire caulking portion 42 in the rear is inserted into the connector housing 32 while being slid along the bottom wall 48 and the slot 49 from the rear of the connector housing 32, the terminal lance 35 projecting upward abuts on a rear end portion 44a of the ceiling 44 so as to be moved down while being pressed. When the terminal 34 is further inserted, the first free end 35a of the terminal lance 35 passes through the engagement portion 33 so that not only the terminal lance 35 is restored to its original state but also the first free end 35a is locked in the front end surface of the engagement portion 33. Accordingly, not only the terminal 34 is locked at a predetermined position in the connector housing 32 but also the front portion of the terminal is positioned by the front wall 46.
When the mating contact 50 is inserted into the insertion hole 47 in the front portion of the connector housing 32, the mating contact 50 is held between the contact plate 39 and the box ceiling plate 36 so that the electric wire W is electrically connected to the mating contact 50.
In the above conventional terminal locking structure 31, to take out the terminal 34 from the connector housing 32, when an unlock jig J is inserted through the unlock hole 45 so as to be brought into contact with the inclined surface of the terminal lance 35 or the vicinity of the first free end 35a in the direction of the arrow B to thereby press down the terminal lance 35, the first free end 35a is disengaged from the engagement portion 33. Accordingly, when the rear end portion of the terminal 34 is pulled back, the terminal 34 can be removed from the connector housing 32.
In this occasion, however, if the inside of the unlock hole 45 cannot be seen so that the unlock jig J is entangled, a root portion 35b of the terminal lance 35 may be deformed by the unlock jig J. Accordingly, there arises a problem that the terminal lance 35 is plastically deformed to spoil its function.